 
 
 
11.3.5  Exact values of rational roots of a polynomial
The rationalroot
command finds rational roots of polynomials.
- 
rationalroot takes one mandatory and two optional
arguments:
- 
P, a polynomial.
- Optionally, α and β, two real numbers.
 
- rationalroot(P) returns the list
of the value of the rational roots of P without
multiplicity.
- rationalroot(P,α,β) returns the list
of the rational roots of P which are in the interval
[α,β].
Examples
Find the rational roots of 2x3−3x2−8x+12:
| rationalroot(2*x^3-3*x^2-8*x+12) | 
Find the rational roots of 2x3−3x2−8x+12 in [1,2]:
| rationalroot(2*x^3-3*x^2-8*x+12,1,2) | 
Find the rational roots of 2x3−3x2+8x−12:
| rationalroot(2*x^3-3*x^2+8*x-12) | 
Find the rational roots of 2x3−3x2+8x−12:
| rationalroot(2*x^3-3*x^2+8*x-12) | 
Find the rational roots of (3x−2)2(2x+1)=18x3−15x2−4x+4:
| rationalroot(18*x^3-15*x^2-4*x+4) | 
 
 
